Chapter III. From Spore To Mushroom

(1) The spore is a single cell, and when it is in a warm, moist place it swells.

(2) The cell absorbs food through its cell wall and divides into two cells.

(3) Each new cell absorbs food and divides until long chains of cells are formed, looking to the unaided eye like threads. Each thread is a hypha, and a tangle of threads is a mycelium.

(4) In the soil the mycelium nourishes itself on decaying vegetable matter, and grows; then, at certain points, the threads mat together to form little balls the size of pin-heads (a).

(b) The pinheads grow to the size of bird-shot.

(c) The bird-shot increase to the size of shoe-buttons.

(5) If the ball is to become a stemmed toadstool, a minute stem appears on the button. The stem and button increase in size. The button is lifted above the soil and expands into a mushroom.

(6) If the button is to become a puff-ball, no stem appears on the button; but it grows, and comes out of the ground a round puffball. (See Plate opposite p. 124.)

From Spore to Mushroom.

If one wishes to learn to distinguish the members of the mushroom or toadstool family, either for the pleasure he may derive from knowing them, or from a desire to distinguish the edible from the poisonous, he must be fa mi1iar with, the typical parts of the fungus plant, and must know the names of these parts.

The edible mushroom of the market {Agaricus campesiris) serves well for study, as it shows some of the characteristics which all the toadstools, mushrooms, brackets, and puffballs have in common.

(1) This mushroom is in shape something like a parasol.

(2) The handle is the stem, or stipe.

(3) The open top is the cap, or pileus.

(4) Under the cap, radiating from the stalk to the edge of the cap, are thin plates - the gills, or lamellae.

(5) When the mushroom is in the button stage, the gills are not visible, for they are covered with a thin sheet of mycelial threads, called the veil. (See coloured plate of Agaricus campestris.)

(6) As the button grows the veil stretches, and finally breaks, leaving a ragged edge to the cap, and a ring or annulus of veil around the stem. The gills of the Agaricus are not fastened to the stem, but are rounded off at the end near the stem, while others, between the long ones, extend from the edge of the cap only far enough toward the stem to fill up the angles formed by the long gills.

Puffball.

Section across gill (magnified).

From Spore to Mushroom.

The surface of the gills is the fruiting portion of the mushroom.

It is here that the spores are formed.

The structure of the fungus plant up to this point has been similar throughout. A loose tangle of threads underground formed the mycelium - the food provider. A more closely matted tangle above ground-formed the stem and cap and veil, and even the central part of the gill - the fruiting parts of the plant.

On the surface of the gill a difference in structure is found, which will be clearly understood from a picture of a thin section cut across a gill.

(1) The central portion of the gill is made by loosely tangled mycelium threads (tr) draping themselves in thin plates from the surface of the cap.

(2) Just outside of this loose mycelium, on either side, are layers of short cells (c), which bear club-shaped bodies standing out over both surfaces of the gills (b).

(3) Each club bears two slender processes (st) at the free end, and each process bears a spore leaf rust on Hepatica triloba.

A small portion of section of gill (highly magnified).

Corn smut.

All corn smuts, wheat smuts, leaf rusts, toadstools, puff-balls, and brackets bear their spores on club-like cells, and for this reason are put in one group, called Basidiomycetes.

The fact that corn smuts and leaf rusts feed on living plants, while toadstools, brackets, and puffballs feed on dead plants, separates them into two groups; the smuts and rustsforming the lower group, and the others the higher group. It is the higher Basidiomycetes which we wish to consider, as this group includes most of the conspicuous fungi, most of the edible, and those fungi which are dangerous because of their resemblance to edible species.

Remembering that toadstools, puffballs, and brackets all start from spores ; that all have the tangled thread-like plants, seeking the dark ; that they all have the spore receptacle in the light, and bear their spores on club-like cells, one can readily understand their being put in one group.

With a few exceptions not necessary for us to consider, all the higher fungi naturally divide into two groups - pouch-fungi (Gasteromycetes), which conceal their spores in a definite rind, or peridium, as the puffballs do ; and membrane fungi (Hymenomycetes), now called Agari-cales, which bear their spores exposed on the surface of gills, pores, spines, or teeth, as the garden mushrooms, the Boleti, the Clavarias, and the Hydnums.